Controllers are used on a wide variety of devices and systems. Some controllers have schedule programming that modifies schedule parameters such as set points as a function of date and/or time. Some device or system controllers that utilize schedule programming include, for example, HVAC controllers, security system controllers, lawn sprinkler controllers, and lighting system controllers.
In one example, HVAC controllers are often employed in monitoring and, if necessary, controlling various environmental conditions within a home, office or other enclosed space. Such devices are useful, for example, in regulating the temperature, humidity, venting, air quality, etc., within a particular space. The controller may include a microprocessor that interacts with other components in the HVAC system. For example, in many modem thermostats for use in the home or office setting, a controller unit may be provided to interact with a heater, blower, flue vent, air compressor, humidifier and/or other components, to control the temperature, humidity or other environmental conditions at various locations within the home or office. One or more sensors located within the controller unit and/or one or more remote sensors may be employed to sense when the temperature and/or humidity (or other environmental conditions) reaches a certain threshold level, causing the controller unit to send a signal to activate or deactivate one or more component in the system.
The controller may be equipped with an interface that allows the user to monitor and adjust the environmental conditions at one or more locations within the building. With more modem designs, the interface typically includes a liquid crystal display (LCD) panel inset within a housing that contains a microprocessor as well as other components of the controller. In some designs, the interface may permit the user to program the controller to activate on a certain schedule determined by the user. For example, the interface may include a menu routine that permits the user to change the temperature at one or more times during a particular day. Once the settings for that day have been programmed, the user can repeat the process to change the settings for the other remaining days.
In some cases, the interface is simply too complex or cumbersome to be conveniently used to inform the user of where the schedule is in relation to the current time and is simply by-passed or programmed by the user to a temperature set point beyond the desired value in an attempt to achieve a desired temperature quickly. Accordingly, there is an ongoing need in the art to improve the ease of use and understanding of the current schedule in a programmable controller.